Slow Horses Season 6 Finale Review: A Decent Season Wrap-Up That's Overshadowed by the Episode's Mysterious Cliffhanger

This review contains full spoilers for Slow Horses Season 6, Episode 6, which is streaming on Apple TV now.

The Slow Horses always find themselves in dire situations in season finales. To that end, the closer of Season 6 is no different. They’re chased and hunted and shot at again and again. They scheme (well, Gary Oldman’s Jackson Lamb does) to save their behinds — remember, Moscow rules. Reece Nesmith (Lenny Rush) gets his hero moment, pulling off a Chekov’s harpoon. In a moment of stillness, River Cartwright (Jack Lowden) has it out with his dear old dad, Frank Harkness (Hugo Weaving), who might have a soft spot for his son after all. The mess with the Russians closes with Clayface Jane (MyAnna Buring) dead and MI5 handing over a fall guy that isn’t Sid Baker (Olivia Cooke, who shamefully only gets three seconds of distant screentime this episode).

And yet, even with the endless game of survival the agents play against their agitators, this finale doesn’t feel particularly novel for a series that has given us 11th-hour twists and feel-bad yet satisfying endings for its five prior seasons. Yes, it closed on a huge cliffhanger that sets Slow Horses up for Season 7 (due out next year — get those theories cranking about what, exactly, took River down), but it was all just a little too clean and conventional in a show that has typically embraced the mess.

To neatly tie up all of the loose ends, the show had to make a few leaps. The most egregious is Diana Taverner (Kristin Scott Thomas, who nevertheless has given a fantastic performance all season). It’s a bit of a stretch to believe that Diana, after an entire season of quadrupling down on denials and obfuscation, would finally decide to come clean and admit to treason, and even more of a stretch to think that Jackson Lamb (Gary Oldman) would be the one to convince her how to play it. It was hardly surprising, although nonetheless satisfying, that Damien Cantor and Peter Judd were made to be patsies for the Russians essentially financing a hit on their own soil, but it was somewhat curious at how easily the Home Secretary accepted Diana’s finger pointing as fact. It still seems Diana will face some consequences, based on the teaser for next season which seems to be Shirley (woohoo!) and Ho-centric, but one would think an accusation of treason would come with a heftier investigation rather than just taking the First Desk at her word.

Cantor (Harry Lloyd), in retrospect, was a somewhat disappointing bad guy. In the end, he only mattered in the context of giving the main characters a headache for a couple days. He never showed off his media influence, aside from one viral interview and that he could eat dinners in fancy restaurants alone. We never get a sense of how his news outlet operated in society, though there were plenty of inferences to be made, of course, but Slow Horses has never shied away from being explicit with an antagonist’s ugliness. Even just last season, Ho’s honey trap and her Libyan terrorist group, seeking revenge for Britain’s heavy hand in their country’s destabilization, had far richer characterization. Here, Cantor was a fairly one-note villain-of-the-season (he barely even speaks during his first appearance in Episode 1), motivated by winning a Russian media distribution contract that was mentioned in a single scene.

Slow Horses Season 6, Episode 6 — Images

Pivoting to the rigamarole of Slough House, their chilling at the posh safehouse by Harkness and his goons. Their flee-and-hide routine in the final showdown in Diana’s holiday home and along the lakeshores has its share of exciting moments. (Also, how the hell did River find his way there?) Having them break off into teams was functionally necessary for these scenes, but the compartmentalization often impacted the momentum of things and came off like a stop-and-start game of fight tactics. No offense, but I don’t want Fire Emblem: Fortune’s Weave in my TV show, thanks. But RIP Emma Flyte (Ruth Bradley), gone too soon but sticking by her word to be the group’s distraction. Louisa Guy (Rosalind Eleazar) also had a scary brush with mortality, but it also wasn’t hugely surprising to see her alive by the end; it would have been too much to kill her off, even for Slow Horses.

The most interesting revelation from that sequence was the curtain-pull on Harkness’s motivations. From that came an actual moment of uncertainty: if he would still go and kill Reece after Cantor called him off. He holds himself to the terms of the job after all. Harkness might have explained away killing Jane as an act of stopping the dangerous pursuer, but it certainly felt bigger than that as he offered River a drink in the aftermath of it all. River letting him get away bookends that short interaction in a meaningful way (and now the show can still deploy Harkness in future seasons).

The last scene back at River’s grandad’s house — where, in a sweet gesture, Sid kept her promise from the last episode, leaving a light on for River — was almost a lovely moment for an agent who’s had a terrible last few days. That final scene of River going for tea, then wine, then collapsing raises a ton of questions, of course. There’s the paranoia around Sid: Did she lure him there? Is she bad after all? More likely, I think, Jim and Jane planted something on one of the objects he touched, knowing that he would return to the house and getting their job done from beyond the grave. Jim did grab the crowbar in Episode 3 when they first broke into the house, and River made a whole show of the residue when he grabbed it. But that seems too obvious. Even though Season 6 laid its tracks maybe too bare, I’m still prepared to be made a fool by Slow Horses again.